I built some surfboards with cloth inlays, and I would always start by washing the cloth in water with white vinegar, supposedly this will fix the color so it doesn't run. You will want cotton because it will lay the flattest and the synthetics won't wet out very well with resin. I think that it would be easiest to lay your cloth down first, directly on the wood, and wet it out with epoxy, squeegee off all the excess, and let it cure till it's slightly tacky but not quite fully cured. Then lay out your glass on the cloth and glass as normal. When you laminate the cloth you will have to make sure you don't have any wrinkles or gaps because they will be really hard to fix. Also, make sure your cloth is fully wet out, with no dry spots, as they will be weak points. I believe that if you put the cloth over the glass it will be hard to get it to lay down right and you will have to put several filler coats on top of it in order to avoid sanding into it. Just my .02, and just one way to do it, but as the other guys have said it's probably better in the long run to just glass normally and then paint it. The cloth will get quite a bit darker once it's wet out, and most camo patterns disappear at a distance anyway.